so again when the Sun fuses four atoms of hydrogen it makes all of this mess happen okay there's one last thing I want to label in here this atom we made can anybody figure out what element this is can you figure out what elements this atom was I probably should have labeled this sooner but what element is this yes that is helium does that make sense that is helium and we can tell because it has two protons so I'm gonna add that in right there okay all right and in case you're interested I will post up a photograph of this full diagram in the discord after this lecture is done okay in case you can't see some of these parts very well you'll all post a picture of it now let's let's take this whole thing and simplify it okay let's simplify this down okay let's make it way easier to digest let's write it as a little bit of a formula okay and in this formula we're gonna have an arrow there we go pointing to the right and on the left hand side of this arrow we're just going to just going to write what the son uses in the fusion and on this side we're gonna talk we're gonna write down everything that survives the process okay so if we look over here what's the only thing that the son is using what's the only thing what are we gonna put on the left-hand side of this equation what is the son using to get all this going I'm crossing off all this stuff because this is what we're looking at over here what is the son using to get this process going for helium's that is correct for sorry for hydrogen's my bad for hydrogen's that is correct so on this side of oh man are you freezing on me again are you freezing on me again reboot reboot no reboot one more time there we go so on this side like you guys were saying it's four hydrogen's so I'm just putting a big four there and an H to mean four hydrogen's the Sun only uses four hydrogen's to make this happen now over here what do we make well we make helium but we only make one of it so I'm just gonna write helium okay we make neutrinos we make two of them so I'm going to write plus two neutrinos now this right here this is a Greek letter you probably haven't seen it before it kind of looks like a V and the wind or like a raptor claw or something just or a tornado that's the Greek letter nu G we usually spell any W and the reason we use that symbol is it's neutrinos so we use the Greek letter nu okay uh and then we make gamma rays how many total gamma rays does the Sun make every time it does this process how many total gamma-ray photons altogether are being made six that is correct it's six if we put them all together if we add these two to these four we get that now I'm not gonna list the positrons because them and the electrons don't survive the process they're kind of like an intermediate step they're not there when this is done so when we're writing down here we just want to say what does the Sun put in and what does it get out so all of this mess breaks down to this one formula right here and don't worry the rest of the lectures not going to be as technical as what we're doing right here we're almost done with this so the son uses four atoms of hydrogen to make one atom of helium two weird ghost particles that your neutrinos and six sorry I forgot the six gamma rays okay so this is how the Sun makes light all right a couple of things we should say about this before we move on to more interesting stuff the Sun is using four atoms of hydrogen to make a new helium so what's happening to the number of atoms in the core of the Sun over time is the number of atoms staying the same is the number of atoms going down or is the number of atoms going up keep in mind that these are not atoms and these are not atoms either okay it's going down it's going down the Sun is slowly losing atoms in its core the amount of hydrogen is decreasing over time faster than the amount of helium atoms we're building up so this is what will cause the Sun to die one day when the Sun runs out of hydrogen atoms to make this fusion go it won't be able to make light the way it's doing right now anymore and that's when the Sun will die in about six or seven billion years so we've still got a pretty big gas tank going but it is depleting where we're getting close to 1/2 of the Sun's core being depleted at this point yay all right now okay uh last couple of things I want to say about this the Sun is making gamma rays that's the type of light it makes is gamma rays the main kind of light that's coming out of the Sun know what's the main kinds of light that are coming out of the Sun yeah that's correct visible and UV the main types of light that the Sun is giving off is visible and UV so something must happen to this light that is made in the core of the Sun on its way out of the Sun to cause it to change into the visible light and UV that we see okay the next thing is this last thing I got to say about this we said this was happening in the core and I also said we cannot see the core so how do we know that this is how it's happening there's a whole bunch of ways you can make light on if we can't see the core how is it that we know that this is what's making the light and not like a bunch of hamsters hooked up little hamster wheels attached to two light bulbs get like powering the light bulbs with their little hamster feet how do we know it's this this one actually I don't actually think you guys will be able to know this one let me ask you this remember these ghost particles these ghost particles these helium atoms they're going to be trapped in the center of the Sun they're going to be trapped in the core because there's a whole bunch of extra gas on top and that's the whole rest of the Sun is pressing down on that core keeping the helium in is that gas gonna block the neutrinos is the gas of the Sun gonna be able to block these neutrinos no no it's not remember I said neutrinos can go through your body they can go through walls they don't like to interact with other matter so that means when they're made they immediately leave the Sun and the Sun is doing this billions and billions and billions of times a second so that means the Sun is constantly shooting out bajillions of neutrinos in all directions hamsters don't make neutrinos potato batteries don't make neutrinos regular fire doesn't make neutrinos but this fusion process does so if we can detect neutrinos coming out of the Sun then we can prove that this is how the Sun is making its light and we have done that we have made some of the the craziest sci-fi looking devices to detect these neutrinos here's an example right here here is a solar neutrino detector this is a giant detector placed under a ground to catch neutrinos from the Sun it's very very complicated how it works but we place these underground because the neutrinos of the Sun can penetrate through the ground and hit this detector and that shields it from other possible disturbances but that also means what's going through your body right now every single second what's going through your body every second of every day neutrinos and a lot of them neutrinos and a lot of them so right now literally billions of neutrinos from the Sun are coming in one side of you and going out the other and you're not even protected at night because if this was the earth and the Sun was over there the neutrinos of the Sun will go through the earth and come out the other side and just go through you then right so we're constantly being bombarded by these things but don't worry again they're not gonna hurt you because they don't really interact with your body almost ever every once in a while one of them will bounce off of you but for every one that bounces off of you billions and billions go through you okay and somebody is asking what happens to them eventually they essentially will just continue to fly through space forever there's just neutrinos flying all over the place out there from every star is sending out tons of neutrinos but they don't tend to affect much of anything again they every once in a while will hit something but in such small numbers that essentially what usually would happen is they'll bounce off of whatever they hit not enough to actually cause any noticeable effect